BACKGROUND Recent studies have revealed that N2O exerts its antinociceptive effect by inducing opioid peptide release in the brain stem, thereby activating the descending noradrenergic inhibitory neurons, which modulate pain processing in the spinal cord. However, the precise neuronal pathways that mediate these events remain to be determined. METHODS Using immunohistochemical and behavioral ...

The dorsal raphe nucleus (DRN) and ventrolateral periaqueductal grey (vlPAG) regions contain populations of dopamine neurons, often considered to be a dorsal caudal extension of the A10 group [mostly found in the ventral tegmental area (VTA)]. Recent studies suggest they are involved in promoting wakefulness and mediate some of the antinociceptive and rewarding properties of opiates. However, l...

Murine models are increasingly used for investigations of sleep, yet no previous studies have characterized cholinergic activation of guanine nucleotide binding proteins (G proteins) in mouse brainstem nuclei known to regulate sleep. This study used in vitro [(35)S]guanylyl-5'-O-(gamma-thio)-triphosphate ([(35)S]GTPgammaS) autoradiography to test the hypothesis that muscarinic cholinergic recep...

The ventrolateral medulla (VLM) modulates autonomic functions, motor reactions and pain responses. The lateralmost part of the caudal VLM (VLMlat) was recently shown to be the VLM area responsible for pain modulation. In the present study, the brain sources of VLMlat afferent fibers were determined by tract-tracing techniques. Following injection of cholera toxin subunit B into the VLMlat, retr...

Electrical stimulation of the dorsal regions of the periaqueductal gray (PAG) leads to defensive reactions characterized as freezing and escape responses. Until recently it was thought that this freezing behavior could be due to the recruitment of neural circuits in the ventrolateral periaqueductal gray (vlPAG), while escape would be mediated by other pathways. Nowadays, this view has been chan...

Numerous physiological and emotionally motivated behaviors, including locomotion, exercise, escape, and attack behaviors as well as passive coping responses, require concomitant activation of motor and sympathetic efferents. Such functional heterogeneity suggests the existence of dual function neurons that can simultaneously coordinate motor and sympathetic output. Because previous physiologica...

Maternal love, which is at the core of maternal behavior, is essential for the mother–infant attachment relationship and is important for an infant’s development and mental health. In addition, maternal love plays important roles in promoting not only the infant’s resilience, but also the mother’s. Therefore, it is crucial to clarify the neural basis of maternal love and related behaviors to un...